POJ 2001 Shortest Prefixes（字典树）

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <algorithm>
#include <string>
#include <vector>
#include <map>

using namespace std;

#define lson l, m, rt << 1
#define rson m + 1, r, rt << 1 | 1
#define ceil(x, y) (((x) + (y) - 1) / (y))

const int SIZE = 35;
const int N = 2e5 + 10;
const int INF = 0x7f7f7f7f;
const int MAX_WORD = 25;

struct Trie {
	int val[SIZE];
	int c;
};

int sz, n;
Trie pn
;
char str
[MAX_WORD];

int newnode() {
	memset(pn[sz].val, 0, sizeof(pn[sz].val));
	pn[sz].c = 0;
	return sz++;
}

void init() {
	n = sz = 0;
	newnode();
}

void insert(char *s) {
	int u = 0;
	for (int i = 0; s[i]; i++) {
		int idx = s[i] - 'a';
		if (!pn[u].val[idx])
			pn[u].val[idx] = newnode();
		u = pn[u].val[idx];
		pn[u].c++;
	}
}

int findstr(char *s) {
	int u = 0;
	for (int i = 0; s[i]; i++) {
		int idx = s[i] - 'a';
		if (pn[u].c == 1)
			return i - 1;
		if (!pn[u].val[idx])
			return i;
		u = pn[u].val[idx];
	}
	return strlen(s) - 1;
}

int main() {
	init();
	while (scanf("%s", str
) != EOF)
		insert(str[n++]);
		
	for (int i = 0; i < n; i++) {
		printf("%s ", str[i]);
		int k = findstr(str[i]);
		for (int j = 0; j <= k; j++)
			printf("%c", str[i][j]);
		printf("\n");
	}
	return 0;
}